Diesel and gasoline prices continue their decline for the sixth straight week. After weeks of decline, however, oil prices rose due to encouraging signs regarding the U.S. and Chinese economies.

The average price of diesel is down 4.8 cents from last week to $3.956, and all regions saw price decrease, according to the Department of Energy's Energy Information Agency. Diesel prices are at their lowest since February, and prices are down 4.1 cents from one year ago.

The price of gasoline is also down this week, by 4 cents to $3.956 per gallon. All regions except West Coast less California experienced decreases. Gasoline prices are down 13.5 cents from one year ago.

Oil is down almost 12% this month because of concerns about slowing global economic conditions, but prices rose this week. Benchmark oil rose $1.09 to finish at $92.57 per barrel Monday in New York. Brent crude increased $1.67 to $108.81 per barrel in London.

Two developments brightened outlooks that oil demand may improve in the U.S. and China. According to a survey by the National Association of Business Economists released this week, economists are slightly more positive about recovery in the job and housing markets. However, they also expect consumer spending, business investment and gross domestic product to remain below historic norms.

Also, the Xinhua News Agency reported that Premier Wen Jiabao said more efforts should be devoted to facilitating China's economic growth, which fell to a nearly three-year low of 8.1% in the first quarter